Deformable diaphragm



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DEFORMABLE DI APHRAGM Filed Oct. 26, 1967 3 Sheets-Sheet l P 2, 1969 M.J. J. PEQUIGNOT 3,464,322

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DEFORMABLE DIAPHRAGM Filed Oct. 26, 1967 3 Sheets-Sheet 5 United StatesPatent 3,464,322 DEFORMABLE DIAPHRAGM Michel J. J. Pequignot, 19 RuePoliveau, Paris Seme, France I Filed Oct. 26, 1967, Ser. No. 678,409Claims priority, appIicatiOnQFrance, Dec. 19, 1966,

Int. Cl. F01b 19/04; F16j 3/00; A61f 1/22 US. C]. 92-91 6 ClaimsABSTRACT OF THE DISCLOSURE In a large number of industrial apparatus,deformable flexible diaphragms are utilized to obtain impulse or pumpingeffects. These diaphragms, which are generally fiat when at rest, aredeformed by the action of pressure of a fluid in contact with one oftheir faces. Under the effect of this pressure, the diaphragm, retainedat its periphery, swells and as it deforms causes a variation of usefulvolume for pumping.

A pumping effect can also be obtained by mechanical action applieddirectly to the diaphragm by displacing the centre of the diaphragm by arod or other similar means.

The present invention has for its object a deformable flexiblediaphragm, characterized in that the said diaphragm is arranged so as tobe deformed by the internal action of a fluid in the structure and thethickness of the said diaphragm.

With this diaphragm, the swelling eflect is produced by an actiondeveloped in the actual interior of the diaphragm instead of beingcaused by an external action.

According to one form of embodiment, the diaphragm is constituted by orassociated with an assembly of tubes of elliptical section, wound in aspiral, in superimposition or in juxtaposed contact, communicating witha source of fluid under pressure. If the tubes are oval, the admissionof a fluid under pressure into these tubes tends to give them a circularform, and the change from the oval shape to the circular shape isaccompanied by a swelling or displacement of the diaphragm. Thisdeformation gives rise to a variation of volume with pumping of thefluid external to the diaphragm.

The accompanying drawings show by way of example one form ofconstruction of the diaphragm according to the invention.

FIG. 1 is a view in cross-section of the diaphragm when at rest.

FIG. 2 is a plan view of the same diaphragm.

FIG. 3 is a view in cross-section of the same diaphragm in the inflatedposition.

FIG. 4 gives a cross section of an alternative form of construction.

FIGS. 5 and 6 show in cross-section a different construction of a convexdiaphragm with a deformation in the opposite sense to that of FIGS. 1 to3.

FIG. 7 shows in cross-section a further form of construction.

FIG. '8 represents an alternative form.

FIGS. 9 to 11 relate to a further alternative form,

FIG. 9 being a perspective view of this alternative, while FIG. 10 is aview in cross-section taken along the line X-X of FIG. 9 showing thediaphragm in the position of rest, and FIG. 11 shows a cross-section ofthe same diaphragm in the active position.

As can be seen from FIGS. 1 and 2, the diaphragm is constituted by atube 10 wound in a spiral. This tube is of oval section and thesuccessive turns are in cont-act, stuck or welded to each other at 11.The outer edge 12 of the spiral thus formed is embedded in a supportformed for example by two parts 13 and 14, clamped together so as togrip the edge 12.

The spiral tube 10 is closed at its central portion 15 and its outerextremity 16 is connected to a source of fluid.

As shown in FIG. 1, when at rest the successive turns of the tube 10 arealigned substantially in the same plane. When a fluid under presusre isadmitted to the tube 10 through the extremity 16, the oval tube 10 tendsto takeup a circular shape. For this reason, the diaphragm beingimprisoned at its edge 12 cannot expand in its own initial plane andtakes up an incurved shape, as shown in FIG. 3.

This inflation is utilized in order to create an impulse or pumpingeffect on one or two fluids in contact with the diaphragm.

When the pressure is removed from the interior of the tube 10, the wholeof the diaphragm re-assumes its flat initial position of FIG. 1 inconsequence of its elasticity or conjointly with the residual pressureapplied against the working face of the said diaphragm.

This diaphragm has the advantage that it does not require for itsoperation any external action by pressure or mechanical action, Thedeformation is caused by an internal action due to the structure of thediaphragm. This results in a substantial reduction of the space which itoccupies.

I A further advantage is that this diaphragm enables the action of animpulse at high pressure and very small volume to be converted to adisplacement of a large volume at low pressure, or vice-versa. Ittherefore permits of large deformations and in consequence of highpumping capacities by injection of a small quantity of fluid under highpressure.

In this way, small differences in volumes with considerable variationsin pressure, such as those produced by the phenomena of expansion orstriction of magnetic or piezoelectric origin may be utilized andamplified.

In addition, this diaphragm can carry out movements of considerableamplitude without it being necessary to enclose it in appropriate spaceshaving substantal bulk.

In accordance with an alternative form shown in FIG. 4, the turns of thetube 10 which form the diaphragm, of an elliptic section with the majoraxes parallel and in contact along the minor axes, are rigidly fixed toone or two thin sheets 17, 18 of elastic material.

Instead of a diaphragm which is flat when at rest and becomes deformedto take-up a convex position, as has been shown in FIGS. 1 to 3, thediaphragm according to the invention may be provided so as to be convexin the position of rest, as shown in FIGS. 5 and 6. The diaphragm isthen constituted by tubular elements 19 of oval or elliptic section, incontact by the extremities of the major axes of the ellipses.

When a fluid under pressure is admitted into the elements 19, thispressure tends to give the tube a circular form 20, as shown in FIG. 6,which has the effect of a shortening the major axis and in consequencecauses a deformation in the sense of a flattening of the diaphragm,giving a pumping efi'ect.

Following another form of construction shown in FIG. 7, the diaphragm isconstituted by adjacent concentric tubes 21, in contact with each otherbut with communication passages 22 from one tube to the next adjacenttube.

According to this form of construction, the diaphragm may be composed oftwo half-shells 21a and 21b obtained by moulding and welded or stuck toeach other so as to form the communication channels 22.

An alternative form illustrated in FIG. 8 shows a diaphragm constitutedby elliptical hollow elements 25 arranged in the form of a pocket havingits concavity on the side 26 of the fluid to be pumped.

When a fluid under pressure is admitted into the elements 25, the wholeassembly is deformed. The elliptical elements take on a circular formand the diaphragm takes up the position 27. This displacement and theresult-' ing variation of the volume ensure a pumping effect on thefluid admitted at 26.

Instead of being produced by a fluid under pressure, the deformation mayof course be effected by means of an internal depression.

The diaphragm according to the invention may be applied to all theutilizations of usual diaphragms in pumping, in measuring or controlapparatus or instru ments, etc.

By reason of its advantages, the diaphragm is particularly adapted tothe production of ingrafted hearts, that is to say pumps which replacethe heart in the circulation of the blood, and especially in pumps ofthis kind actuated by a magnetic or piezoelectric effect.

FIGS. 9 to 11 show a form of construction which is more particularly butnot exclusively applicable to a pump forming an artificial heart. Thisartificial heart. designed so as to be ingrafted, can be placed in thesame position as the natural heart.

This device is composed of a juxtaposition of two series 28, 29 oftubular elements having an elliptical section. These tubular elements28, 29 are juxtaposed so as to form a pocket having the general shape ofa heart and are connected together at the lower point 30.

These different elements 28 or 29 are connected to each other, eitherdirectly by appropriate orifices, or by collectors. The two series 28and 29 are separated by a partition 31. In this way, each series ofelements 28 or 29 represents a ventricle of the heart having analternating action.

When the assembly of tubes 28 receives internallya fluid under pressure,these tubes are deformed and tend to take-up a circular form. Thisdeformation shortens the wall 28 which tends to come into the position28a in proximity to the partition 31, producing a variation of volumecorresponding to the space 32 and imparting impulses on the fluidcontained in the said space, for example blood.

The same effect is produced by the wall 29 which is deformed by theeffect of fluid admitted into the elliptical tubes and takes up theposition 29a with a corresponding displacement of the fluid contained inthe space 33.

The walls 28 and 29 thus take-up alternately the positions of FIG. 10and FIG. 11, reproducing the natural movements of the heart.

I claim:

1. A deformable diaphragm for impulsing and pumping fluids, comprisingat least one tubular element of noncircular cross section, said at leastone element being disposed in a plurality of juxtaposed turns that aresecured laterally to each other and that communicate with each otherdefining a continuous diaphragm surface, said at least one elementconstituting substantially the whole of the diaphragm from the centralportion of the diaphragm out to the margin of the diaphragm, and meansto connect said at least one element to a source of fluid under pressurewhereby admission of said fluid into said at least one element causesdeformation of the cross section of said at least one element duringinflation of the diaphragm and movement thereof transverse to saiddiaphragm surface.

2. A deformable diaphragm as claimed in claim 1, said at least onetubular element being wound in the form of a continuous spiral from thecenter of the diaphragm out to the periphery of the diaphragm.

3. A deformable diaphragm as claimed in claim 1, and at least onedeformable sheet secured to at least one lateral surface of thediaphragm.

4. A deformable diaphragm as claimed in claim 1, said at least onetubular element being formed of concentric tubular portions thatcommunicate laterally with each other.

5. A deformable diaphragm as claimed in claim 1, which is flat andsubstantially circular in its undeformed condition.

6. A deformable diaphragm as claimed in claim 1, which has the form of arounded pocket in its undeformed condition.

References Cited UNITED STATES PATENTS 737,154 8/1903 Sayer 9292 X1,619,866 3/1927 Hoeschen 92--91 2,212,128 8/1940 Richter 92-92 X2,289,549 7/1942 Norstrom 92-91 2,376,634 5/1945 Tellkamp 92-912,376,635 5/1945 Tellkamp 92-91 2,549,597 4/1951 Harris et a1. 92-92 X3,327,322 6/1967 Norton 3-l 3,343,864 9/1967 Baer 92-92 X 3,379,4114/1968 Vanderjagt 92-92 X MARTIN P. SCHWADRON, Primary Examiner I. C.COHEN, Assistant Examiner U.S. Cl. X.R. 31-1, 1.2; 9298

